Radio pagers (also known as selective call receivers) having a plurality of alerts are well known. It was common before numeric display pagers became available for a radio pager to have a plurality of predetermined selective call addresses, each associated with a telephone access number that could be dialed by callers to send pages to the associated selective call address. Typically, an indication, e.g., a unique alert tone or alert cadence, was generated in response to receiving a page directed to the selective call address. By partitioning potential callers into several different groups, each given a different telephone access number to call, a user could attain some degree of knowledge of the source of the call. For example, a user could give a first telephone access number to business associates, a second number to friends, a third number to relatives, etc. By noting the unique alert accompanying a page, a user was able to discern which telephone access number was dialed to send the page, and thus which of the groups of callers probably originated the page. A significant drawback to this approach of call source identification is that assigning multiple telephone access numbers to a pager is expensive. Another drawback resulted from the limited number of unique addresses and corresponding telephone access numbers possible for each pager.
The arrival of the numeric display pager significantly reduced the need to partition callers into separate groups dialing separate telephone access numbers. By utilizing numeric display paging, callers could dial a single telephone access number to send a call-back number (entered by the caller using, for example, a tone dialing telephone set) that the page recipient could then call to contact the caller by telephone. In many instances the page recipient could discern the identity of a familiar caller by recognizing a familiar call-back number, e.g., the number of the page recipient's home or office, or that of an important client. This ability largely eliminated the need for the expensive multiple telephone access number approach of source identification.
Still, there are situations that can impair one's ability to discern the identity of even an important caller from a displayed call-back number. For example, the call-back number might be that of a relatively new business associate and not yet committed to the page recipient's memory, or perhaps the display might be poorly lighted, making it difficult to read.
Thus, what is needed is a way to aid a user in discerning that a call is from a predetermined subset of important callers without the user's having to memorize call-back numbers or having to read a poorly lighted displayed number. A way is needed that does not require expensive multiple telephone access numbers for a single pager.